# Open Rate: What It Measures and What It Can't Tell You

> A plain explanation of email open rate for people doing outreach, with a worked example, the mistakes to avoid and what to do with the number.

Open rate is the percentage of delivered emails that were recorded as opened. It is calculated by dividing the number of unique opens by the number of emails delivered, then multiplying by 100.

That is the whole definition. The tricky part is knowing what the number actually tells you, and what it doesn't.

## How opens get counted

Most email tools track opens with a tiny invisible image placed in the email. When the recipient's email app loads that image, the tool records an open.

This method has gaps you should know about:

- **Images blocked:** some people and some company mail systems don't load images, so a real read is never counted.
- **Automatic loading:** some email apps and privacy features load images on their own, so an open can be recorded when nobody read anything.
- **Security scanners:** some business mail filters open links and images to check them, which can create opens that aren't human.

So treat open rate as a rough signal, not a precise count.

## Why it matters when you're doing outreach

Even with those gaps, open rate is useful for a few practical jobs.

**Spotting delivery problems.** If a campaign that normally gets steady opens suddenly drops close to nothing, your emails may be landing in spam. That's a cue to check your sending setup, such as [SPF, DKIM and DMARC](https://getclient.pro/blog/set-up-spf-dkim-dmarc-for-cold-email), and whether your sending domain needs a rest.

**Comparing subject lines.** The subject line and sender name are most of what someone sees before deciding to open. Testing two subject lines on similar lists gives you a rough comparison. A list of [cold email subject line ideas](https://getclient.pro/resources/cold-email-subject-line-ideas) is a good place to start.

**Deciding who gets which follow-up.** Opened and not-opened are different situations. Someone who never opened probably never saw your pitch, so a fresh angle or a new subject line makes sense. Someone who opened but didn't reply saw it and needs a different nudge.

## A concrete example

Say you run a small web design studio and email 200 local restaurants you found on Google Maps.

- 200 emails sent
- 10 bounce, so 190 are delivered
- 76 unique recipients are recorded as opening

Your open rate is 76 ÷ 190 × 100 = **40%**.

Now look further. Of those 76 openers, 4 replied, and 1 booked a call. The open rate looks healthy, but the email body or offer is what decides the replies. If you only watched opens, you might think the campaign worked well, when the real question is why 72 people read it and said nothing.

You could then split your next step:

1. The 114 who didn't open get a short follow-up with a new subject line.
2. The 72 who opened but didn't reply get a follow-up that adds one specific detail, such as a quick note about their site's mobile menu.

That split is the core of a sensible [follow-up sequence](https://getclient.pro/learn/follow-up-sequence). The [not-opened follow-up strategy](https://getclient.pro/blog/not-opened-follow-up-strategy) post goes deeper on the first group.

## Common mistakes

**Treating opens as interest.** An open means an image loaded. It doesn't mean the person read, liked or remembered your email. Replies and booked calls are the numbers that pay you.

**Comparing your number to someone else's.** Open rates vary with the audience, the list quality, the tracking method and the email apps your recipients use. Compare your campaigns against your own past campaigns instead.

**Chasing opens with clickbait.** A misleading subject line can raise opens and lower trust in the same move. Write a subject that honestly matches the email.

**Ignoring list quality.** Sending to old or guessed addresses causes bounces and can hurt your sending reputation, which then drags down opens on every campaign. Build a clean [lead list](https://getclient.pro/learn/lead-list) and verify it before sending.

**Testing on tiny samples.** If you send 20 emails per version, a couple of random opens can swing the result. As a rule of thumb, wait until each version has gone to a decent number of people before deciding a winner, and treat small differences as noise.

**Reading opens as counts.** Many tools show whether someone opened, not reliably how many times. Even where a count exists, repeated opens can come from forwarding or scanners. Use opened or not opened, and leave it there.

## What to do next

Use open rate as a health check and a routing signal, then put your attention on replies.

- **Track it per campaign** so you notice sudden drops.
- **Fix delivery first** if opens fall sharply. Consider whether you should [use a secondary domain for outreach](https://getclient.pro/blog/use-a-secondary-domain-for-outreach) to protect your main one.
- **Test one thing at a time**, usually the subject line, and keep the rest of the email the same.
- **Branch follow-ups** on opened versus not opened, rather than sending everyone the same second email.
- **Judge the campaign on replies and meetings**, not opens.

The branch is yes or no only, which fits how unreliable open counts are anyway. You can also verify a list before sending to cut bounces. New accounts get 100 free credits without a card; see [plans and credits](https://getclient.pro/pricing) for details.

## Frequently asked questions

### Does open rate use emails sent or emails delivered?

It's normally calculated on delivered emails, meaning sent minus bounces. Check which one your tool uses before comparing numbers between tools or campaigns.

### Can I turn off open tracking?

Many email tools let you, and some senders do so because the tracking image adds code to the email. You lose the open signal, so you'd judge campaigns on replies and clicks instead.

### Why does my open rate look higher than expected?

Automatic image loading by some email apps and security scanners can record opens that no person made. A high open rate with very few replies is often a sign of this, or of an offer that isn't landing.

### Is a unique open different from a total open?

Yes. A unique open counts each recipient once, no matter how many times the email was loaded. Total opens count every load. Unique opens are the more useful figure for open rate.

### What affects open rate the most?

Whether the email reaches the inbox, who it appears to be from, and the subject line. List quality and sending setup affect the first, so fix those before rewriting subject lines.

Source: https://getclient.pro/learn/open-rate